Flexible rotary tool



June 1, 1954 -r 2,679,778

FLEXIBLE ROTARY TOOL Filed April 2, 1953 In van for Lea 22's Z Kid/77 aW mm 0W i a .i fa/veg Patented June 1, 1954 UNlTED STATES ATENT OFFlEFLEXIBLE ROTARY TOOL Application April 2, 1953, Serial No. 346,433

3 Claims.

The present invention relates to flexible rotary tools, and inparticular to a structure rendering such tools flexible.

Numerous tools such as drills, screw drivers and socket wrenches arefrequently needed in tight places where the location of the work makesordinary inflexible tools difficult or impossible to handle. It is knownthat such tools may be rendered flexible in various ways, and thepresent invention is directed to a simple structure for that purpose.

It is a general object of the present invention to join two shankportions of a rotary tool by means of a flexible coiled spring.

It is a particular object of the invention to pinch the shank within thespring by a forced fit.

It is still another object of the invention to provide either a shank orspring strand or both of such cross section that the tightness of thefit between them is assured.

Various other and ancillary objects and advantages of the invention willbecome apparent from the following description and explanation of thepresently preferred forms of the invention shown in the accompanyingdrawing, in which:

Fig. 1 represents a bar wrench of conventional right-angular formembodying the invention.

Fig. 2 is a plan view of the wrench as seen in Fig. 1.

Fig. 3 is a cross section of the wrench shown in Fig. 1 and is taken online 3-3 thereof.

Fig. 4 shows one manner of using the wrench of Fig. 1.

Fig. 5 represents any other type of rotary tool, specifically a screwdriver with a Philips head.

For the present invention, any tool which is used in a rotary manner,either a bar wrench, a screw driver, or a drill, has its main straightshank divided into two portions which are normally endwise separated. Inaccordance with the present invention, a flexible coil spring isemployed to connect the separated shank portions. The shank portions andthe spring are so designed and related to each other that the shank maybe force-fitted into the end of the spring to give a sufiiciently tightunion for the uses of the particular tool. Of course, these uses mayvary over a wide range, but the normal and practical uses thereof arecontemplated as the principal goal.

Although either one or both of the two separated shank portions may beround in cross section, it is preferred that each portion has apolygonal cross section, thereby to provide corner vmember to be turned.

lines running generally lengthwise of the shank into which the coils ofthe spring may forcibly engage. Where a polygonal cross section isemployed, it may be triangular, quadrilateral, 0r many-sided, with orwithout regularity in design. A regular polygonal form of bar isrepresented in Fig. 1 by the material conventionally used when a cut endthereof fits a socket in a This has a regular hexagonal cross section,and the corner lines of the shank are straight lines. However, ifdesiredv a twist may be introduced without in any way departing from theutility of the polygonal cross section for the present invention.

In Fig. 1 a common bar wrench with a hexagonal cross section is cut intotwo portions 18 and ii, the longer section Iii having the usual rightangular extension l2 thereof as a structure useful as a handle when theopposite end is the working end. With the shank portions IE3 and Hendwise separated, they are connected by a coil spring l5, one end It ofwhich has a forced fit with the shank portion II, the other end llhaving a forced fit with the shank portion it. The shank portions areforced into the spring thereby slightly to expand the coils. They may beforced in axially, or screwed into place, the preferred manner dependingupon which metal is the harder. The normal tendency of the coils tocontract causes the coils to grip the shank and make contact therewithat the corner lines one of which is designated I8.

The strand of which the spring i5 is made is preferably circular springwire whereby the area of contact of the coils at the corner lines I8 islimited and thereby the gripping force between the coil and shank isgreater per unit of area. The contact of the corner lines [8 with theround of the wire to a slight degree upsets the metal of one part or theother forming contact areas tending to lock the union against twistmg.

Fig. 4 illustrates a corner in which a socket head screw 20 is mounted,in which screw the wrench of Fig. 1 is inserted for rotary use at theillustrated angle. In Fig. 4 the designated wall 21 is so located that astandard inflexible socket wrench, such as that in Fig. 1 Without thespring, could not be turned through a complete revolution. By means ofthe flexible connection the screw 29 may be readily turned by the wrenchof Fig. 1 through several complete revolutions.

The wall 23 surrounding the socket 22 in screw 20 may be considered as asort of jig holding the wrench section II in its axial position forrotation. Thus, the invention may be applied to produce flexible drillswhen there is provided a suitable jig or its equivalent to hold theworking end of the tool, namely a drill, in axial alinement for itsdrilling operation.

Fig. 5 represents another form of tool embodying the invention, namely ascrew driver having a conventional handle 30, a straight shank 31inserted in the handle, a Philips head 32 enclwise separated from theshank 3 I, and a connecting spring 33. The two shank portions 3| and 32of the screw driver are hexagonal, which is conventional for many formsof such tools with a Philips head. The Philips head for a screw driveris preferred over a single blade screw driver, because the Philips headhas in effect the four quadrant blades 35 which in use of theillustrated tool in a flexed position hold the head in the Philips slotof the screw being worked. A single blade screw driver tends to slideout of its slot at certain positions in its operation, as may be wellunderstood. However, it is not intended that a single blade screw driverhead is inoperable in connection with a flexible shank, because thistype of flexible tool is well known, although otherwise constructed.

The present invention is not to be considered as limited to or by theembodiments above illustrated and described, and numerous variations andapplications may be made without departing from the invention asexpressed in the appended claims.

I claim:

1. A rotary tool comprising two endwise separated straight shankportions each polygonal in cross section, and a coiled spring connectingsaid portions, one shank portion having at its free end handle-meansextending laterally therefrom to facilitate rotatary manipulation ofsaid shank portion, the other shank portion having at its free end aworking structure adapted to engage an element to be turned thereby as aresult of rotary movement imparted to said shank portion through saidspring, the other ends of each shank portion being housed within an endportion of the spring, said end portions of the spring being slightlyexpanded by a forced fit whereby engagement of the spring and each shankis limited to the corner lines of the polygonal shank.

2. A rotary tool comprising two endwise separated straight shankportions each polygonal in cross section, and a coiled spring of wirewhich is round in cross section connecting said portions, one shankportion having at its free end handle-means extending laterallytherefrom to facilitate rotary manipulation of said shank portion, theother shank portion having at its free end a working structure adaptedto engage an element to be turned thereby as a result of rotary movementimparted to said shank portion through said spring, the other ends ofeach shank portion being housed within an end portion of the spring,said end portions of the spring being slightly expanded by a forced fitwhereby engagement of the spring and each shank is limited to the cornerlines of the polygonal shank.

3. A flexible bar wrench for hexagonal sockets comprising two endwiseseparated hexagonal shank portions, one being a straight portion and theother having a right-angle bend therein, and a coiled spring connectingsaid portions, the end of each shank portion being housed within an endportion of the spring, said end portions of the spring being slightlyexpanded by a forced fit whereby engagement of the spring and the shankis limited to the six corner lines of the hexagonal shank.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 211,918 Lombard Feb. 4, 1879 519,354 Sheppard May 8, 18941,187,497 Canfield June 20, 1916 2,372,930 Bovee Apr. 3, 1945 FOREIGNPATENTS Number Country Date 637,927 Great Britain May 31, 1950 1,010,858France Mar. 26, 1952

